Flame retardant and intumescent compositions

ABSTRACT

Novel adjuvants and combinations thereof are provided which have the properties of importing flame-retardancy and intumescence to polymeric materials. The new adjuvants comprise halogenated and phosphorus-containing adjuvants of diallyl chlorendate and mineral acid salts of phenylbiguanidine derivatives. The latter may be advantageously combined with a wide variety of phosphoruscontaining compounds, including especially, novel diallyl chlorendate derivatives to provide intumescent films and coatings.

United States Patent Kuehn 1 Feb. 4, 1975 FLAME RETARDANT ANDINTUMESCENT COMPOSITIONS [56] References Cited [75] Inventor: ErichKuehn, Wilmington, Del. UNITED STATES PATENTS 73 Assignee; AtlasChemical Industries, Inc" 3,037,044 5/1962 Bruson et a1. 106/15 FPWilmington DeL 3,257,337 6/1966 Schoepfle et a1 260/2.5 AJ 3,396,1298/1968 Yeadon et al 260/77.5 R [22] Filed: Oct. 26, 1973 3,525,7088/1970 Clark et a1. 260/45.85

[21] Appl' 409895 Primary ExaminerLucille M. Phynes Related US.Application Data [62] Division of Ser. No. 297,397, Oct. 13, 1972, Pat.No. [57] ABSTRACT 3,801,333, which is a division of Ser. No. 104,149,Jan. 5, 1971, PM NO. 3,723138, which is a division Novel ad uvants andcombinations thereof are proof Ser, No, 726,538, M 3, 1963, Pat N0-vided which have the properties of importing flame- 3,639,535.retardancy and intumescence to polymeric materials.

The new adjuvants comprise halogenated and phos- [52] US. Cl..... 106/15FP, 260/2.5 AJ, 260/2.5 FP, phorus-containing adjuvants of diallylchlorendate and 260/29.6 HN, 260/29.6 N, 260/29.6 MP, mineral acid saltsof phenylbiguanidine derivatives. 260/29.6 MN, 260/45.85, 260/45.9 NP,The latter may be advantageously combined with a 260/75 T, 260/77.5 AM,260/78.5 T wide variety of phosphorus-containing compounds, in- [51]Int. Cl (109d 5/18 cluding especially, novel diallyl chlorendate deriva-[58] Field of Search... 260/25 AJ, 2.5 FP, 29.6 HN, tives to provideintumescent films and coatings.

260/29.6 N, 29.6 MP, 29.6 MN, 75 T, 77.5 AM, 45.85, 45.9 NP; 106/15 PF10 Claims, No Drawings This application is a division of copendingapplication Ser. No. 297,397, filed Oct. 13, 1972, now U.S. Pat. No.3,801,333, which is a division of application Ser. No. 104,149, filedJan. 5, 1971, now US. Pat. No. 3,728,138, which in turn is a division ofapplication Ser. No. 726,538, filed May 3, 1968, now US. Pat. No.3,639,535.

This invention relates to compositions having flameretardantcharacteristics, to compositions having intumescent characteristics, tocomponents which impart such characteristics to such compositions and tomethods of preparation of such components and compositions.

The need for flame-retardant construction and decorating materials inthe building arts and trades has gained substantial importance in recentyears and, accordingly, the search for components suitable for impartingflame-retardant characteristics to such materials as paints, coatings,films, foams and the like, has been unremitting and wide-spread. Withrespect to films and coatings, a very desirable characteristic, inaddition to simple flame-retardancy, that is, in addition to theself-extinguishing and non-burning properties of the material, is thatof intumescence whereby the coating or film swells or bubbles up whensubjected to heat or flame to provide a coherent shield spaced apartfrom the substrate which protects the same from attack by fire.Optimally, therefore, components introduced into films and coatings forthe purpose of rendering them fire-resistant will include not onlycomponents which impart flame-retardancy thereto, as that term isordinarily understood, but also components which impart thecharacteristic of intumescence as well.

It is accordingly, an object of this invention to provide novelcompositions which impart the characteristics of flame-retardancy topolymeric materials when incorporated thereinto.

It is another object of this invention to provide compositions whichimpart characteristics of flameretardancy and intumescence to polymericmaterials, especially films and coatings, when incorporated thereinto.

It is another object of this invention to provide polymeric compositionshaving the characteristic of flameretardancy.

It is another object of this invention to provide polymeric compositionshaving the characteristic of intumescence.

lt is another object of this invention to provide method for preparingpolymeric materials having characteristics of flame-retardancy and bothflameretardancy and intumescence.

in accordance with this invention, the foregoing objects and stillfurther objects are broadly achieved by providing classes of compoundssuitable for incorporation into polymeric materials to impartflameretardancy and, in some cases, intumescence thereto. A novelflame-retardant composition as provided in accordance with thisinvention is characterized by the following generalized formula:

a Cl co cu caxca x c1 0 l l I Cl I T co cn ciixca x wherein X isselected from the group consisting of halogen atoms having an atomicweight greater than 30 and the group PO(OR) in which R is selected fromthe group consisting of alkyl radicals containing from 1 to 4 carbonatoms, alkenyl radicals containing from 1 to 4 carbon atoms, alkenylradicals containing from 1 to 4 carbon atoms substituted with at least 2halogen, atoms having an atomic weight greater than 30. a phenyl groupand a phenyl group substituted with a halogen atom having an atomicweight greater than 30.

Products defined by the formula given above may be prepared by thehalogenation in the presence of butyl alcohol and at temperatures belowC., perferably between about 0C. and 30C. of di-allyl chlorendate, anester which is itself an easily available commercial product and whichmay also be easily prepared by reacting one mole of chlorendic anhydridewith two moles of allyl alcohol. Chlorendic acid or its anhydride may beprepared by conventional chemical processes by reactinghexachlorocyclopentadiene with maleic acid or maleic anhydriderespectively. A preferred halogen for use in the preparation ofcompounds useful to impart fire-retardancy to films, coatings, foams andsimilar polymeric materials in accordance with this invention isbromine. The following chemical equation illustrates the preparation ofa typical brominecontaining component suitable for use in thepreparation of fire-retardant polymeric materials in accordance with thepresent invention:

\ i CO2CH2CH=CH2 COzCHzCHBICHzBI 3 4 range of about 70C. to about 200C.Alkyl groups (13) forming the phosphoric acid ester may be methyl,ethyl, propyl or butyl radicals. The aryl group may be the phenylradical or a halophenyl radical. The following generalized chemicalequation is illustrative of the preparation of phosphorus-containingcompositions Cl conforming to the formula set forth above:

C1 C0 CH CHClCH Cl CO CH CHClCH Cl n (23. L. co ca crmrca sr C c1 PO (oca 2 clf cw c1 CO2CH2CHCH2PO (oc u 2 cl w/- CO CH CHBrCH Br 1 7 Cl 1CO2CH2CHCH2PO (oc a 2 H c PO (CC/1H9) 2 C4H9OH 4NaOP (OR) 2 (51) C1PO(OC2H5)2 H 7 1 CO 2C1{2CHCH2PO(OCZIIS) 2 PO (OR) 2 H I c1 COZCHZCHCHZPOwR) 2 C1 "CO2CH2CHCH2PO (oc n 2 l 4NaBr c PO (OCZHS) 2 ClCO2CH2CHCH2-Po (0R) 2 i H (e) d1 PO (OR) 2 cl 1:0(OC6H5) 2 c1CO2CH2CHCH2PO (oc n 2 wherein R is selected from the group consisting ofan c1: CO2CH2CHCI-I2PO (oc ri 2 alkyl group containing from 1 to 4carbon atoms, a phe- 40 H nyl group and a halogen substituted phenylgroup.

Suitable compounds which may be used for reaction with the halogenateddiallyl chlorendate to produce the phosphorus-containing derivativeinclude sodium dibutyl phosphite, sodium dimethyl phosphite, potassium 5diphenyl phosphite, sodium di(chlorophenyl) phosphite, trimethylphosphite, sodium diethyl phosphite, tripropyl phosphite and others.

The following are representative compounds useful in the preparation offlame-retardant polymeric materials in accordance with this invention:

PO pe s 2 co ca co cu cn-cu o (OCH CHBrCH2Br) 2 PO(OCll The following isa specific example ofthe preparation of a halogenated diallylchlorendate suitable for use in accordance with the present invention:

EXAMPLE 1 The reaction is carried out in a suitable 3-necked flaskequipped with stirrer, reflux condenser and dropping funnel. 467 grams 1mole) ofdiallyl-chlorendate are dissolved in 200 ml. of butanol. Thereaction flask is then placed into an ice-water bath and from a droppingfunnel 320 grams 2 moles) of bromine are added dropwise to saturatecompletely the diallyl chlorendate. The bromine may be added until thesolution is no longer decolorized by addition of more bromine at thispoint 2 moles of bromine per mole of diallyl chlorendate have been addedand the resulting reaction product is a brominated diallyl chlorendatehaving a chemical structure which accords with formula (a) above.

The following is a specific example ofthe preparation of aphosphorus-containing product suitable for use to impart flame-retardantcharacteristics to polymeric materials in accordance with the presentinvention:

EXAMPLE 2 In a suitable vessel, 92 grams (4 moles) ofsodium aredissolved in 200 grams of butanol and 776 grams (4 moles) of dibutylphosphite. When all sodium is dissolved or has been converted to sodiumdibutyl phosphite, the resulting solution is then added to the productobtained in Example I at about 50C. 60C. The addition of sodium dibutylphosphite to the brominated diallyl chlorendate results in a reactionwhich is exothermic in character. When all sodium dibutyl phosphite hasbeen added, the mixture is refluxed at a temperature between 100C. lC.for 3 hours to ensure complete condensation. The condensation iscomplete when no more sodium bromide is formed. After cooling, thesolution is washed salt free and the butanol is removed under vacuum.The resulting product has low viscosity, is clear and slightly brownish.The product conforms in its chemical structure to formula (c) above. Theyield is about 98%.

Another class of flame-retarding compositions useful in the practice ofthe present invention is exemplified by mineral acid salts of compoundsbroadly characterized by the following generalized formula:

lflltf tenn wherein X is a halogen having an atomic weight greater thanand n is a number from 0 to 5.

Compounds comprised by the preceding formula may be prepared, ingeneral, by reacting a suitable acid salt of aniline and dicyandiamidein molar proportions in an acid medium. As a practical matter, anymineral acid may be used; however, hydrochloric acid is preferred. Thefollowing chemical equation illustrates the preparation ofa typicalflame-retardant composition of the kind characterized by the formula (2)above:

H2N c NHCN The following are representative compounds useful in thepreparation of flame-retardant materials in accordance with thisinvention:

NH NH Br u u a uc Nac NH -nc1 Q 11253304 Cl 2 I-IZNC NHC NH liCl H NCNllC Nll Br Br The following specific example illustrates thepreparation of a typical composition suitable for use to impartflame-retardancy to plastic and polymeric materials conforming toformula (2) above:

EXAMPLE 3 The reaction is carried out in a 1000 ml., 3necked flaskequipped with reflux condenser and stirrer. 129.6 grams of anilinehydrochloride (1 mole) is dissolved in 300 ml. of water. Thereafter, 84grams (l mole) of dicyandiamide (cyanoguanidine) are added to thesolution. After addition of a small amount of HCl, the mixture is heatedto reflux temperature. During the heating, the dicyandiamide also goesinto solution. After about 30 minutes of refluxing, a greenish-graysolid precipitates. The precipitate, which isphenylbiguanidinehydrochloride, is filtered off and washed with water.After drying, the phenylbiguanidinehydrochloride may be ground into afine powder to be used as a flame-retardant pigment component. Theproduct conforms in its chemical structure to formula (g) above.

In accordance with the present invention, fireretardant coatings, films,foams and such polymeric materials may be prepared by incorporationthereinto from about 5% to about 60% by weight of the total polymericcomposition of the chlorendic acid ester derivative hereinbeforedescribed and characterized by formula l above or from about 25% toabout 60% by weight of the total polymeric composition of, thephenylbiguanidine derivative hereinbefore described and characterized byformula (2) above.

In general, the flame-retarding components described herein arecompatible with a wide variety of polymeric materials and resins fromwhich films or coatings and, in some cases, even foams may be made.Among those resinous or polymeric materials with which saidflame-retardant components are compatible are, for example, polyesterresins, polyurethane resins, cellulose derivatives, polymeric vinylresins, epoxy resins and others.

Polyester resins which are useful in accordance with this inventioninclude linear polyesters made by reacting glycols or other diols withdibasic organic acids and abundantly described in the art. Such linearpolyesters comprise the reaction products of dihydric alcohols such asethylene glycol, diethylene glycol, propylene glycol, bisphenol A,prodendro bisphenol A. higher molecular weight polyglycols and numerousother diols and aliphatic dibasic carboxylic acids such as adipic acid,phthalic acid, sebacic acid, fumaric acid and maleic acid and others inproportion to completely esterify the hydroxyl group present in thedihydric alcohol. Cross-linked polyesters made by reactingpolyfunctional alcohols, such as glycerol, with the aforementionedaliphatic dibasic carboxylic acids in sufficient proportion to esterifythe hydroxyl groups present in the polyhydric alcohol. Unsaturatedpolyesters crosslinked with a vinyl-type monomer, such as styrene, maybe used. Polyesters which may be used in the practice of the presentinvention comprise, but are not restricted to, those described and theirmethod of preparation disclosed in U.S. Pat. Nos. 2,453,644; 2,593,787;2,409,633; 2,443,735; 2,443,741; 2,450,552; 2,255,313; 2,512,410;2,634,251;

2,662,069 and 2,662,070, all hereby incorporated by reference.

Epoxy resins, characterized by the presence of the group,

are useful in the practice of the present invention and comprisepolymeric reaction products of polyfunctional halohydrins, such asepihalohydrins with polyfunctional hydrogen-donating reactants, or theirsalts, such as polyfunctional phenols, alcohols, amines, acids and theirsalts. Typical of these is the reaction product of an epihalohydrin,such as epichlorohydrin and bisphenol A. The preparation of such anepoxy resin is described in U.S. Pat. No. 2,500,449 in whichepichlorohydrin is reacted with bisphenol at 100C. in the presence ofsufficient alkali to bind the hydrochloric acid formed. The resinsformed vary according to the proportions of reactants and reactionconditions. Epoxy resins of the kind useful in the practice of thisinvention are further described in U.S. Pat. Nos. 2,324,483; 2,444,333;2,503,726; 2,558,949; 2,500,600; 2,467,171; 2,528,932; 2,582,985 and2,615,007, all hereby incorporated by reference.

The fire-retardant components of the present invention may be used incoatings prepared from synthetic polymer emulsions. Monomers from whichsuch synthetic high polymers may be prepared are in generalcharacterized by the formula atoms are linked directly to the ethyleniccarbon atoms and in the true vinyl monomers R,, R and R are allhyvention may be used in coatings made of cellulose derivatives andinclude coatings made from cellulose esters, such as cellulose nitrate,cellulose phosphate, cellulose acetate, cellulose acetate butyrate andothers. Coatings formed from cellulose ethers may be used. Thesecomprise, for example, methyl cellulose, ethyl cellulose, methyl ethylcellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethylhydroxyethyl cellulose and benzyl cellulose.

In accordance with the present invention, the abovedescribedflame-retardant additives may be used in the preparation of a widevariety of polyurethane films, coatings and foams. Coatings and foamscomprising multiple urethane linkages formed by the reaction of anisocyanate and a compoundcontaining a hydrogen atom or atoms reactivetherewith as, for example, hydroxyl-bearing compounds such as polyestersand polyethers having terminal hydroxyl groups.

Suitable polyesters useful in the preparation of polyurethane coatingsand foams in accordance with this invention may be obtained byesterification condensation reaction of an aliphatic dibasic carboxylicacid with a glycol or triol or mixture thereof in such proportion thatthe resultant polyesters possess predominantly terminal hydroxyl groups.Aliphatic dibasic carboxylic acids which may be used to prepare suchpolyesters comprise adipic acid, fumaric acid, sebacic acid and phthalicacid, for example, and suitable alcohols include ethylene glycol,diethylene glycol, trimethylol propane and others.

Fatty acid glycerides may be used as the hydroxylbearing component inthe preparation of the polyurethane polymers of the present inventionand comprise those having a hydroxyl number of at least 50, such ascastor oils, hydrogenated castor oils or blown natural oils.

Polyesters, generally, which may be used in the preparation ofpolyurethane polymers are described in U.S. Pat. Nos. 2,453,644;2,593,787; 2,409,633; 2,443,735-41; 2,450,552; 2,255,313 and 2,512,410,all hereby incorporated by reference.

Polyether hydroxyl-bearing compounds which may be used to prepare bothpolyurethane coatings and foams in accordance with this inventioncomprise those having a functionality of two or more, i.e., polyetherswhich are diols, triols, tetrols, pentols or hexitols. Particularlysuitable polyethers are polyoxyalkylene ethers of polyhydric alcohols oramines such as polyoxyalkylene glycols, polyoxyalkylene bisphenol A,polyoxyalkylene sorbitol, polyoxyalkylene methyl glucoside,polyoxyalkylene pentaerithritol, polyoxyalkylene sucrose,polyoxyalkylene trimethylolethane, polyoxyalkylene trimethylol propane,polyoxyalkylene diethylene triamine and polyoxyalkylene glycerine. Thepolyoxyalkylene ether of the polyhydric alcohol may be prepared,ifdesired, by reacting an alkylene oxide compound with a selectedpolyhydric alcohol in the conventional manner. The overall range ofalkylene oxide groups per molecule may vary within a range of about 2 toabout 80 and the alkylene oxides which may be used comprise ethyleneoxide, propylene oxide, butylene oxide and others.

More specifically, among the hydroxy-bearing compounds which may be usedto prepare polyurethane polymers useful in the practice of the presentinvention are polyoxyalkylene bisphenol A containing from 2 to 20oxyalkylene groups per molecule and including the polyoxyethylene,polyoxypropylene and polyoxybutylene derivatives; 1,2,6-hexanetriol;dipropylene glycol; propylene glycol; ethylene glycol;polyoxyethy1ene(2- )cyclohexane dimethanol; polypropylene glycol (M.W.I000); glycerine, trimethylol propane; polyoxypropylene(40)sorbitol;po1yoxypropy1ene(20)methy1 glucoside; polyoxypropylene(llisosorbide aswell as many other polyhydric alcohols indicated, for example. in U.S.Pat. No. 2,843,568, hereby incorporated by reference. Accordingly,aromatic, aliphatic and cycloaliphatic hydroxy compounds may be utilizedin the preparation of polyurethane polymers. Ethylene oxide, propyleneoxide and butylene oxide derivatives of such polyhydric alcohols may beused, as well as hydroxylterminated polyesters derived from saturated orunsaturated dibasic acids, simple glycols and modifying trihydricalcohols. In many cases it will be desirable to use two or morepolyhydric alcohols in combination to produce a polyurethane polymerhaving the desired characteristics.

A wide variety of organic isocyanate compounds may be used to preparethe polyurethane polymers useful in the practice of the presentinvention, among which are included toluene diisocyanate, diphcnyldiisocyanate, triphenyl diisocyanate, chloro-phenyl-Z,4-diisocyanate,ethylene diisocyanate, 1,4-tetramethylene diisocyanate, p-phenylenediisocyanate, hexamethylene diisocyanate, 3,3'-dimethyl-4,4-biphenylenediisocyanatc, 3,3-dimethoxy-4,4-biphenylene diisocyanate, polymethylenepolyphenyl polyisocyanate (PAPl), diphenylmethane-4,4-diisocyanate andothers.

Suitable catalysts for the preparation of polyurethane foams compriseamine catalysts and tin catalysts and mixtures thereof. Representativeamine catalysts are N-alltyl morpholines, such as N-methyl morpholineand Nethyl morpholine; tertiary amines, such as trimethyl amine,triethyl amine, tetramethylguanidine, triethylene diamine, N,N,N,Ntetramethyl-l ,3-butane diamine; piperazine and piperazine derivatives,such as N-methyl piperazine. These amines may be present in amounts fromabout 0.05% to about 2% by weight of the hydroxyl-bearing compoundsreacted with the isocyanate compound. Among the suitable tin catalystsare included dialkyl tin laurates, such as dibutyl tin laurate, dibutyltin di-Z-ethyl hexoate, dibutyl tin diacetate, stannous oleate andstannous octoate. Tin catalysts may be present in amounts from about0.1% to about 1.0% by weight of the hydroxyl-bearing compound used inthe reaction.

Examples of useful surface active agents which may be used in thepreparation of polyurethane foams comprise water-solublesiloxane-oxyalkylene block copolymers as described in U.S. Pat. No.2,834,748, to Bailey, et al., condensates of ethylene oxide with ahydrophobic base formed by condensing propylene oxide with propyleneglycol having generally the formula HO(C H O),,(C H.,O),,(C H O),.H.Another class of surfactants is comprised by the formula Othersurfactants comprise the polyoxyalkylene esters of long chain fattyacids and sorbitan, such as polyoxyethylene (20) sorbitan monolaurate,polyoxyethylene(4)sorbitan monolaurate, polyoxyethylene(20- )sorbitanmonopalmitate, polyoxyethylene(20lsorbitan monostearate,polyoxyethylene(20)sorbitan tristearate, polyoxyethy1ene(5)sorbitanmonooleate and others.

A foaming agent, such as a halogenated saturated aliphatic hydrocarbonor a mixture of such hydrocarbons,

EXAMPLE 4 Moisture-curing Flame-retardant polyurethane coating Aprepolymer is prepared which is the product of reaction of toluenediisocyanate and polyoxypropy1ene(10)sorbitol in proportion to provide aratio of isocyanate groups to hydroxyl groups in the end product ofabout 4.5 to l. The reaction is carried out in a one-liter, 3-neckedround-bottom flask equipped with stirrer, nitrogen inlet, droppingfunnel and reflux condenser. 392 grams of toluene diisocyanate areplaced in the flask at room temperature under nitrogen and stirring. 114grams of polyoxypropylene(|O)sorbitol are then added over a 30 minuteperiod of time. The reaction is exothermic and the temperature should beheld at C. (using a heating mantle) for 5 hours. After cooling theprepolymer is ready for use. The free isocyanate content is about 28% byweight. The final curing of the urethane coating is achieved by reactionof the free isocyanate groups of the prepolymer with atmosphericmoisture.

A clear varnish is prepared by first dissolving 41.7 grams of theurethane prepolymer in 10.4 grams of cellosolve acetate, 5.2 grams ofmethyl ethyl ketone and 5.2 grams of toluene with slow stirring. Thesequence of solvent addition is unimportant. When the prepolymersolution has become clear, 37.5 grams of the phosphorus containing allylchlorendate derivative of Example 2 is stirred into the solution withslow mixing. The varnish is then ready for use.

EXAMPLE 5 A urethane prepolymer is prepared as in Example 4.

A varnish is then prepared by dissolving 17.3 grams of Y the urethaneprepolymer in 17.5 grams of cellosolve acetate, 8.75 grams of methylethyl ketone and 8.75

grams of toluene with slow stirring. When the prepolymer solution hasbecome clear, 47.7 grams of the phenylbiguanidine hydrochloride ofExample 3 are stirred into the solution with slow mixing. The resultingvarnish may be used wherever a flame-retardant varnish is required.

The following is a specific example of the preparation of aflame-retardant polyurethane foam in accordance with the method of thepresent invention:

EXAMPLE 6 Rigid Polyurethane Foam Formulation Component A by WeightPolymethylcne polyphenyl isocyanate 40.0

(Mondur MR) Component B Polyoxyethylene( l)sorbitol 35.0

Dimethylethanol amine 1.0

Dibutyl tin laurate 0.1

Siloxane-oxyalkylene block copolymer 0.6

surfactant (L53l0, Union Carbide) Allyl chlorendate derivative ofExample 2 10.0

Trichlorofluoromethane 13.0

Component B in the above formulation is prepared by adding together in asuitable vessel each of the named ingredients sequentially in the orderand the amounts specified while mixing thoroughly with a high speedmixer. To the homogeneous mixture is then added quickly and in a singleaddition the entire specitied amount of organic isocyanate (ComponentA). The combined components are then mixed at high speed with alaboratory mixer for about 10 seconds, after which the mixture is pouredinto a 1 gallon paper cup and allowed to foam. The foam may bedetermined to have the following properties as indicated:

Cream Time (sec) Foam Time (sec) 55 Tack free Time tsec.) 42

Burning Test Seconds Inches (ASTM D1692-59T) In accordance with animportant modification of this invention flame-retardant and intumescentfilms and coatings may be produced by combining therein with a mineralacid salt ofa phenylbiguanidine derivative, as defined by formula (2)above, a suitable phosphoruscontaining flame-retardant component such asthose exemplified hereinafter. In accordance with this invention,intumescent polymeric materials may be made by incorporating thereintofrom about 5% to about 60% by weight of a combination of flame-retardantadditives including as necessary ingredients the phenylbiguanidinederivative characterized by formula (2) above and aphosphorus-containing flame-retardant material. The porportions of saidnecessary flame-retardant ingredients in said polymeric materials mayvary from a ratio of about 1 part by weight of said phenylbiguanidinede-,

rivative to 1 part by weight of said phosphoruscontaining compound to 20or more parts by weight of said phenylbiguanidine derivative to about 1part by weight of said phosphorus-containing compound, provided,however, that if the phenylbiguanidine derivative should be used inamounts less than about 25% by weight of the composition, then theconcentration of said phosphorus-containing compound must be not lessthan 4% by weight of said polymeric material.

A wide variety of phosphorus-containing compounds may be used incombination with the phenylbiguanidine derivative characterized byformula (2) above to provide flame-retardant intumescent polymericmaterials. Preferred phosphorus-containing flame-retardant additives foruse in this connection are those subsumed under formula (1) above. Manyother phosphorus- 'containing materials may be used, however, includingorganic esters and partial esters of phosphoric acid, phosphoric acidsalts and organic phosphites and phosphonates. Representative of themany phosphoruscontaining materials which may be used, for example, aretertiary phosphites, such as trimethyl, triethyl, tripropyl and tributylphosphite, tri(2 ethylhexyl) phosphite, tridecyl phosphite (iso),trioctadecyl phosphite, triphenyl phosphite, diphenyl pentaerythritolphosphite and phenylneopentyl phosphite; secondary phosphites, such asdimethyl, diethyl, dipropyl and dibutyl phosphite, diallyl phosphite,di(2 ethylhexyl) phosphite, diphenyl phosphite, dioctadecyl phosphiteand dilauryl phosphite; phosphonate and phosphorothionate esters, suchas dimethyl methyl phosphonate, diallyl ally] phosphonate, dimethylbenzyl phosphonate, trimethyl phosphorothionate and ethylene phenylphosphorothionate; organophosphorus compounds, such asbis(hydroxymethyl) phosphinic acid, methyl phosphonic acid, trimethallylphosphite and triallyl phosphate; alkyl acid phosphates having thegeneralized formula I (Oli) (RO) 2P OH and (ROhP 0 wherein R is aradical selected from the group consisting of methyl, ethyl, propyl,butyl, phenyl and cresyl, such as methyl acid phosphate, nbutyl acidphosphate, amyl acid phosphate and lauryl acid phosphate, as well asmany other phosphoruscontaining flame-retardant additives such as thosedisclosed in U.S. Pat. Nos. 2,691,567; 2,683,168; 3,206,474; 2,795,609;3,014,944; 3,014,956; 3,042,701 and 3,058,941, all hereby incorporatedby reference.

The following is an illustrative example of the preparation of aflame-retardant, intumescent coating in accordance with the method ofthe present invention:

EXAMPLE 7 Flame-retardant Nitrocellulose Lacquer Formulation Thenitrocellulose, wetted with 30% butanol, is placed in a solution vesseland the diluent (xylene) is added in the quantity specified. Thereafter,the solvents butyl acetate and cellosolve acetate are added. The mixtureis stirred until the nitrocellulose solution is clear. Finally, flameretardant additives of Example 2 and 3 are added in the quantitiesindicated.

It should be appreciated that the phenyl-biguanidine derivative acts asa pigment and consequently requires grinding as may any other pigment.Standard equipment used in paint manufacture may be used for thispurpose. It should be further appreciated that the flame-retardantadditives may be incorporated into the coating either separately or inthe form of a composition prepared in advance for such purpose. Thefollowing are representative examples of compositions suitable for usein the preparation of intumescent flameretardant coatings in accordancewith this invention:

EXAMPLE 8 Ingredient Parts by weight Compound exemplified by formula (g)1 Compound exemplified by formula (c) 1 EXAMPLE 9 1 Parts by weightIngredient Compound exemplified by formula (g) Compound exemplified byformula (d) 1 EXAMPLE 10 Ingredient Parts by weight Compound exemplifiedby formula (h) Compound exemplified by formula (e) EXAMPLE IngredientParts by weight Compound exemplified by formula (k) 10 Compoundexemplified by formula (f) 1 EXAMPLE Tributyl phosphlte EXAMPLE 4Ingredient Compound exemplified by formula (g) 4 Diethyl phosphite 1EXAMPLE Ingredient Parts by weight Compound exemplified by formula (g) 8Dimethyl methyl phosphonate 1 EXAMPLE l6 Ingredient Parts by weightCompound exemplified by formula (h) 12 n-hutyl acid phosphate 1 EXAMPLEIngredient Parts by weight Compound exemplified by formula (j) 2Triallyl phosphate 1 The following are further representative examplesof the preparation of flame-retardant intumescent coatings according tothe method of the present invention:

EXAMPLE l8 lntumescent Nitrocellulose Lacquer Formulation NitrocelluloseRs hsec. (30% butanol) Wood resin (Vinsol, Hercules. Inc.)Phosphorus-containing derivative of Example 2 Phenylbiguanidinehydrochloride of Example 3 Colloidal silica (Cabosil M-S) AcetoneToluene Cellosolve Acetate The nitrocellulose, wetted with 30% butanol,is placed in a solution vessel and the diluent (toluene) is added in thequantity specified. Thereafter, solvents acetone and cellosolve acetateare added. The mixture is Parts by weight stirred until thenitrocellulose solution is clear and then the wood resin and colloidalsilica are added with stirring to achieve a homogeneous solution andmixture. Then are added flame-retardant additives of Examples 2 and 3 inthe quantities specified.

EXAMPLE 19 Inturnescent Polyurethane Coating EXAMPLE 20 IntumescentPolyvinyl Acetate Emulsion Based Coating Formulation Ingredient byWeight Polyvinyl Acetate Emulsion 48.0 Flame-retardant derivative ofExample 2 13.0 Flame-retardant derivative of Example 3 26.0 Water 13.0

A polyvinyl acetate emulsion is prepared from the following materials inthe following manner:

Ingredient by Weight Water 43.] 1 Dodecyl benzene sulfonate 0.1 lPolyoxyethylene (20)nonyl phenol 1.32 Borax 0.25 Potassium persulfate0.21 Vinyl Acetate 55.0

EXAMPLE 21 F lame-retardant lntumescent Polyester Formulation IngredientParts by Weight Polyester resin (Atlac 382) 40 Styrene 40 Halogenatedhydrocarbon (tetrachloro- 20 diphenyl ether) Allyl chlorendatederivative of 5 Example 2 Methyl ethyl ketone peroxide solution 1 Cobaltnaphthenate l The polyester resin of the above formulation is anunsaturated polyester resin prepared in the conventional manner byreacting l mole of polyoxypropylene(2)bisphenol A with 1 mole of fumaricacid. 40 grams of the polyester resin are dissolved at room temperaturein 40 grams of styrene while stirring lightly. When all of the polyesterresin has dissolved, 20 grams of halogenated hydrocarbon are added andthe mixture stirred until homogeneous. Thereafter, 5 grams of theflameretardant additive of Example 2 are added together with catalysts.The catalysts are mixed in by hand. After catalyzation, the polyestersolution is poured into glass molds and cured at room temperature. Thefollowing are results of ASTM D-635 flame tests performed on Va inchcastings: V4 inch in 48 sec.; $4 inch in 3 min.

Having thus described my invention, I claim:

1. A flame-retardant polymeric composition containing from about 5% toabout 60% by weight of said composition of a flame-retarding agentselected from the group consisting of a mineral acid salt of a compoundcharacterized by the generalized formula:

NH NH ll ll H2N NHC NH wherein X is a halogen having an atomic weightgreater k than 30 and n is a number from 0 to and mixtures of saidmineral salt with a phosphorus-containing flameretardant compound,provided that if said mineral acid salt to be the sole flame-retardingagent, said mineral acid salt be present in a concentration of not lessthan about 25% by weight of said composition and that if saidflame-retarding agent be a mixture providing a concentration of saidmineral acid salt of less than about 25% by weight of said composition,the concentration of said phosphorus-containing flame-retardant compoundin said polymeric composition be not less than about 4% by weight ofsaid composition.

2. A flame-retardant polymeric composition according to claim I whereinsaid phosphorus-containing compound is characterized by the generalizedformula:

wherein R is selected from the group consisting of alkyl radicalscontaining from 1 to 4 carbon atoms, alkenyl radicals containing from 2to 4 carbon atoms. alkenyl radicals containing from 2 to 4 carbon atomssubstituted with at least 2 halogen atoms having an atomic weightgreater than 30, a phenyl group and a phenyl group substituted with ahalogen atom having an atomic weight greater than 30.

3. A flame-retardant polymeric composition according to claim 1 whereinsaid phosphorus-containing compound is characterized by the formula:

n c1 PO (oc u 2 and wherein said mineral acid salt is characterized bythe formula:

NH NH i i HZNC NHC NH HCl 2O 5. A moisture-curing polyurethane coatingcomposition according to claim 3 containing about 4.3% by weight of saidcomposition of said phosphoruscontaining compound and about 43.4% byweight of said mineral acid salt.

6. A polyvinyl acetate emulsion based coating according to claim 3containing about 13.0% by weight of said composition of saidphosphorus-containing compound and about 26.0% by weight of said mineralacid salt.

7. A polyester film according to claim 3 containing about 5 parts byweight of said composition of said phosphorus-containing compound.

8. A method of preparing a polymeric composition which comprises thesteps of incorporating thereinto from about 5% to about 60% by weight ofsaid composition of a flame-retarding agent selected from the groupconsisting of a phosphorus-pontaining compound characterized by thegeneralized formula:

c1 co cn caxca x cl c c1 co cn cnxci-t x wherein X is -PO(OR) in which Ris selected from the group consisting of alkyl radicals containing fromI to 4 carbon atoms, alkenyl radicals containing from 2 to 4 carbonatoms, alkenyl radicals containing from 2 to 4 carbon atoms substitutedwith at least 2 halogen atoms having an atomic weight greater than 30, aphenyl group and a phenyl group substituted with a halogen atom havingan atomic weight greater than 30 and a mineral acid salt of a compoundcharacterized by the generalized formula:

NH rm wherein X is a halogen having an atomic weight greater than 30 andn is a number from O to 5 and mixtures of said mineral salt with aphosphorus-containing compound, provided that if said mineral acid saltbe the sole flame-retarding agent, said mineral acid salt be present ina concentration of not less than about 25% by weight of said compositionand that if said flameretarding agent be a mixture providing aconcentration of said mineral acid salt of less than about 25% by weightof said composition, the concentration of said phosphorus-containingcompound in said polymeric composition be not less than about 4% byweight of said composition.

9. A method of preparing a polymeric composition which comprises thestep of incorporating thereinto from about 5% to about 60% by weight ofacompound characterized by the form ula:

wherein X is selected from the group consisting of the halogens havingan atomic weight greater than 30 and the group PO(OR) in which R isselected from the group consisting of alkyl radicals containing from 1to 4 carbon atoms, alkenyl radicals containing from 2 to 4 carbon atoms,alkenyl radicals containing from 2 to 4 carbon atoms substituted with atleast 2 halogen atoms having an atomic weight greater than 30, a phenylgroup and a phenyl group substituted with a halogen atom having anatomic weight greater than 30.

10. A composition of claim 1 wherein the flameretarding agent isamineral salt of a compound characterized by the generalized formula:

NH I

wherein X is a halogen having an atomic weight greater than 30 and n isa number from 0 to 5.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 13,864,135

DATED 1 February 4, 1975 mvmmms Erich Kuehn It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 12, line 65, reads:

Cellosolve acetate 4.25

should read:

Cellosolve acetate 14. 25

Signed and Sealedthis eleventh Day of November 1975 [SEAL] Arrest:

RUTH C. MASON C. MA'RSHALL DANN rllllslmg Jf (mnmissimu'r nflarents um]Trademurkx

2. A flame-retardant polymeric composition according to claim 1 whereinsaid phosphorus-containing compound is characterized by the generalizedformula:
 3. A flame-retardant polymeric composition according to claim 1wherein said phosphorus-containing compound is characterized by theformula:
 4. A moisture-curing polyurethane coating composition accordingto claim 3 containing about 37.5% by weight of said composition of saidphosphorus-containing compound.
 5. A moisture-curing polyurethanecoating composition according to claim 3 containing about 4.3% by weightof said composition of said phosphorus-containing compound and about43.4% by weight of said mineral acid salt.
 6. A polyvinyl acetateemulsion based coating according to claim 3 containing about 13.0% byweight of said composition of said phosphorus-containing compound andabout 26.0% by weight of said mineral acid salt.
 7. A polyester filmaccording to claim 3 containing about 5 parts by weight of saidcomposition of said phosphorus-containing compound.
 8. A method ofpreparing a polymeric composition which comprises the steps ofincorporating thereinto from about 5% to about 60% by weight of saidcomposition of a flame-retarding agent selected from the groupconsisting of a phosphorus-containing compound characterized by thegeneralized formula:
 9. A method of preparing a polymeric compositionwhich comprises the step of incorporating thereinto from about 5% toabout 60% by weight of a compound characterized by the formula:
 10. Acomposition of claim 1 wherein the flame-retarding agent is a mineralsalt of a compound characterized by the generalized formula: